The main standout in Locusts profile is ODD, which makes him able to do shootouts comfortably. While he does sit at a PanO standard of BS 12, he can engage relatively well against most other models without access to any level of MSV or Fire Ammunition. Having an above-average PH 12, he can be able to dodge against most things that Locust can use when not he is going to favor shooting a long-range target. Along with his PH 12, the Drop Bear profile can put it down at a close distance 75% of the time when throwing his Drop Bear. While having a CC 20, he has no access to MA to give him courage or benefit from lowering the opponent's CC skill. While he does have access to Shock and DA CC Weapons, Locust should not be getting into Close Combat most of the time.
Having both Infiltration and Stealth, Locust can go and be able to sneak up on the opponent if there is the orders to back him up. Most of the profiles include a D-Charge, which can help score the Demolition Classified Objective or use it to get a AP+EXP weapon on a TAG or so (bearing in mind he should not be in CC most of the time).
As mentioned before with ODD but to add to it, ODD does give a layer of protection for his meager ARM 1 and BTS 3. Which means that you still want to keep Locust in cover. With BTS 3, it can resist some hacking attacks but for the most part he is going to go down against a determined Killer Hacker. With Stealth, it gives him the ability to move around and not prompt an ARO if you keep out of sight.
With his Drop Bears profile, Locust can be used in a defensive role to set-up a defense against warbands getting to close or lock down a distant objective from the opponent's specialists.
+Having access to D-Charges on his Breaker Combi and Hacking profiles, he can use it to deal with more heavier armor in CC (thought not recommended most of the time) or to complete the Sabotage Classified objective. +With being able to not prompt an ARO in the Opponent's ZoC via Stealh, this can be use to set-up a few Drop Bears along his flank and then blow it up if so desired. +Referring back to Drop Bear, he can simple set them up like mines in order to make it hard for the opponent to get close to the objective and/or spend a couple turns trying to remove them.
While ODD can be a pain, access to MSV or fire can help to deal with his ODD. Along with that, he tends to want to be more close ranged, so forcing him to be at range might be of benefit. Other things in dealing with him is direct template or impact if you get the perfect angle. Otherwise, Locust is just an ordinary man and has less potential to keep himself hidden compared to Croc-Men.
Outside of this, the BTS might be a slight annoyance to some weapons reliant on going through BTS (Viral being the most prominent) to make his BTS rolls viable. But with not access to Bioimmunity he is going to go down all the same.
Also remember, KHDs ignore repeater firewalls which a lot of PanO bots carry around the midfield. Dont be afraid to use them to go after this guy, or just walk up to him out of LoS. It's not perfectly safe, but with burst on your side and a better toolkit even than the AHD profile, they can be effective counters for the one specialist profile.
Remember to keep an eye out for traps, or for defenses too order intense to deal with. As with all things infinity, clearing out 4-5 orders and contesting other objectives might be a better use of your time than eliminating the one bug. Come back for him when he's forced to move out of cover, or doesn't have the orders to do things right.
With only access to one specialist profile, Locust will have lot of competition with Croc-men in Vanilla PanO due to Croc-men having access to specialist profiles and minelayer. As well, Croc-men have access to TO Camo instead of ODD in which means they can go into hidden deployment and go back into marker state if needed. However, what Locust does have in comparison in Vanilla PanO is the access to Breaker Combi-Rifles in dealing with low-tech factions like Ariadna or Haqq to an extent. In this context, Locust acts more as an active turn piece and a little more flexibility in setting up Drop Bears to control the board rather than being an objective grabber. Another option for 1 more point is to take Marksman rifle to get more long range with the ability to use shock from Marksmanship L1. This said, he misses out on having D-Charges or Drop Bears.
In Neoterran Capitaline Army, he provides much needed infiltration up the field, in which can be used to throw down Drop Bears around objectives and lock them down. As mentioned, his down side is that he does not have the ability to start in hidden deployment or in marker state.
You will want him supported though, consider Peacemakers, Croc Men in Vanilla, or other Locusts in NCA. On their own each profile is readily countered by most lists, and will be a juicy and inviting target worth a LOT of points. Defending with mines and drop bears is something of an option, but remember how many cheap HFTs and Auxbots will gladly trade for this nightmare, and how many MSV troops [or KHDs] will be floating around. This can be used as a strength though. Combining specialist, board control, and low SWC alternative active turn killer, these things are rightly prioritized for a reason. Every layer of defense you build for them, whether that's a Fusilier ML link, a KHD hexa waiting to use a peacemaker repeater, or just forcing people to clear out peacemakers themselves, or the Croc man that gets off that vexing to counter ARO from HD, are orders they will spend and risks they have to take. The alternative being to try to bypass large areas of midfield that you effectively control. Even putting them on Suppressive Fire can be brutal if they can be kept safe from HFT/DTWs. Even MSV troops aren't usually at their best shooting into -6, and anything else will struggle to break hitting on 5s with -12 mods from ODD, SF, and Cover. Whatever you do, DO not leave them unsupported.
Being that Locust does not have Camo-Marker state or no access to hidden deployment, he requires a little more finesse to set up. While having Infiltration, it is wise to leave him well-hidden behind some total cover until he has the turn to go. However, you still want him set up close to objectives in order to score or secure them with Drop Bears.
If you are going first in the active turn, it will be good to get him into position to start getting close to and putting pressure on the opponent. That said, you do not want him to go up too far and leave him unsupported from the main force so he is easy pickings. Instead, set up to provide a nuisance towards enemy units trying to move up by laying down some Drop Bears or put him in suppression fire. If you do get the sabotage classified objective, then set up near an building in the opponent's have to score the classified objective for it.
Active Turn Role
In the active turn, Locust wants to be taking out low-bts targets to thin the ranks or set up drop bears to hold down key objectives. Being that he lacks heavy power to deal with TAGs or up-armored HIs, he wants to be hidden away and out of sight of those as much as possible.
With the Marksman Rifle, he can provide longer range firepower against line troopers (and since the Marksmanship Rifle loadout has Marksmanship L1, it makes him scarier in thinning out single-wound models without any immunities to it).
With no real option for a strong ARO weapon save for Boarding Shotgun, Locust is going to be either hiding or being in suppression fire with his Breaker Combi or Marksman rifle. If playing with his AHD loadout and has a repeat net around the board, it can be used to deter and control hackable HIs from being too eager from running up the board with Carbonite.